#import <Foundation/Foundation.h>
@interface Person : NSObject {
  NSString* _firstName;
  NSString* _lastName;
}
@property (atomic, readonly) NSString* fullName;
/// @brief 可以复制指针来复制对象可能是由于NSCopy协议
@property (copy, atomic, readwrite) NSString* firstName; 
@property (copy, atomic, readwrite) NSString* lastName;
- (id) init;
- (id) initWithFirstName: (NSString*) firstName_ LastName: (NSString*) lastName_;
- (NSString*) fullName;
@end